Fix rebase issues

Author: sgrif

src/librustc/infer/canonical.rs

@@ -250,8 +250,6 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> {
                 let ty = match ty_kind {
                     CanonicalTyVarKind::General => {
                         self.next_ty_var(
-                            // FIXME(#48696) this handling of universes is not right.
-                            ty::UniverseIndex::ROOT,
                             TypeVariableOrigin::MiscVariable(span),
                         )
                     }

src/librustc/infer/region_constraints/mod.rs

@@ -634,6 +634,8 @@ pub fn region_universe(var_infos: &VarInfos, region: Region<'_>) -> ty::Universe
         ty::ReVar(vid) => var_infos[vid].universe,
         ty::ReLateBound(..) =>
             bug!("region_universe(): encountered bound region {:?}", region),
+        ty::ReCanonical(..) =>
+            bug!("region_universe(): encountered canonical region {:?}", region),
     }
 }
 

src/librustc/traits/select.rs

@@ -1514,7 +1514,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         assert!(!skol_trait_ref.has_escaping_regions());
         match self.infcx.at(&obligation.cause, obligation.param_env)
                         .sup(ty::Binder(skol_trait_ref), trait_bound) {
-            Ok(InferOk { obligations, .. }) => true,
+            Ok(InferOk { .. }) => true,
             Err(_) => false,
         }
     }

src/librustc/ty/mod.rs

@@ -1394,7 +1394,7 @@ impl<'tcx> ParamEnv<'tcx> {
     /// Trait`) are left hidden, so this is suitable for ordinary
     /// type-checking.
     pub fn empty() -> Self {
-        Self::new(ty::Slice::empty(), Reveal::UserFacing, ty::UniverseIndex::ROOT)
+        Self::new(ty::Slice::empty(), Reveal::UserFacing)
     }
 
     /// Construct a trait environment with no where clauses in scope
@@ -1405,15 +1405,14 @@ impl<'tcx> ParamEnv<'tcx> {
     /// NB. If you want to have predicates in scope, use `ParamEnv::new`,
     /// or invoke `param_env.with_reveal_all()`.
     pub fn reveal_all() -> Self {
-        Self::new(ty::Slice::empty(), Reveal::All, ty::UniverseIndex::ROOT)
+        Self::new(ty::Slice::empty(), Reveal::All)
     }
 
     /// Construct a trait environment with the given set of predicates.
     pub fn new(caller_bounds: &'tcx ty::Slice<ty::Predicate<'tcx>>,
-               reveal: Reveal,
-               universe: ty::UniverseIndex)
+               reveal: Reveal)
                -> Self {
-        ty::ParamEnv { caller_bounds, reveal, universe }
+        ty::ParamEnv { caller_bounds, reveal }
     }
 
     /// Returns a new parameter environment with the same clauses, but